Rivet breaker and the like



Mar. 3, 1925.

L. E. DAVIS RIVET BREAKER AND TH LIKE Filed Aug. 2, 1920 2 Sheets-Sheet 1 w @"I w Mar. 3, 1925. 1,528,532

L. E. DAvls mvET BREAKER AND THE' LIKE Filed Aug. 2. 1920 2 sheets-sheet 2 w w w I h1 W y wm, l mw mm, w w M W g a A M WMX\\\Q Patented Mar. 3, 1925..

UNITED STATES LOG-EE E. DAVISQOF HINCKLEY, ILLINOIS.

:R-IvET BREAKER AND THE LIKE.'

Application filed August 2, 1920. Serial No. 400,577.

T0 all whom t may concern:

Be it known that I, LOGIEE E. DAVIS, a citizen of the United States, Aresiding at Hinckley, in the county of De Kalb, in the State of Illinois, have invented certain new and useful Improvements in Rivet Breakers and the like, of which the following is a specification.

The invention has reference to pneumatic tools of the type commonly known as rivet. breakers; and the general aim of the invention is to provide a tool of this type which is of a very practical and highly efficient character.

In tools of the kind referred to, the valve means for controlling the admission and exhaust of pressure fluid has been in the form yof a unitary mechanism located at the handV or rear portion of the tool. This arrangement is objectionable for thereason that the pressure fluid is unable during the 4forward or driving stroke of the piston to eX- haust with sufficient rapidity to prevent a cushioning of the piston, thus reducing the force of its impact upon the cutting implement and hence the eiiiciency'of the tool.

The principal object of my invention is to overcome this diiiculty by providing near the forward end of the tool barrel an exhaust port with a valve for controlling the same adapted to be actuated in the operation of the main pressure fluid controlling valve of the tool.

A further and morespecific object of the invention is to provide .a construction and arrangement of parts which is of a simplified and otherwise practical character avoiding to a maximum degree the 'use of screws, bolts and other parts which are apt to work loose in the use of the tool to; the great danger of the operators. n

In the accompanying drawings I` vhave illustrated a preferred embodiment of the invention wherein the valve means at the forward end of the tool is actuated by means of a mechanical connection with the valve means at the rear end of the tool. Obviously, however, the invention is not limited to the precise construction and arrangement herein illustrated and described for I recognize that various changes may be made without departing from the spirit and vscope of the invention as expressed in the appended claim. Y

Referring now particularly to the drawings, Figure 1 is a plan view of a tool of a tool .17 is arranged to slide. `compression spring 1S i 1s preferably yemembodying the features of my invention. Fig. 2 is a fragmentary sectional view on an enlarged scale showing particularly the means for coordinating the valves at the rear and forward ends of the tool. Fig. 3 is a fragmentary transverse sectional view taken substantially in the plane of line 3 3 of Fig. 1. Fig. 4 is a fragmentary sectional view showing in detail the main valve in position to permity of the exhaust of pressure fluid from the rear end of the cylinder upon the return of the piston, the view being taken substantially in the plane of line 4 of Fig. 5. Fig. 5 is a fragmentary vertical sectional view through the tool.

Fig. 6 is a transverse sectional view through the forward end of the tool, taken substantially in the plane of line V6--6 of Figs. 5 and 8. Figs. 7 and 8 are fragmentary sectional views taken substantially inthe plane of line 7 of Fig. 6 and showing the valve means at the forward end of the tool in different operative positions.

The tool comprises generally a barrel or cylinder 10 having a piston 11 operable therein, and at its forward and` rear end, respectively, a tool holder 12 and a head 13 embodying the controlling mechanism for the tool. f

The cylinder 10 may be of'any preferred construction and f size. ever, it is made of a` substantial length so that the piston 11 therein'may .have a long `and hence powerful stroke.

Preferably, how- The tool holder 12 may also be kof any prefered construction.. Herein it consists of a sleeve let of cast steel or the like suitably secured upon the forward kend of the tool cylinder as by being pressed thereon. At its forward end said sleeve is internally threaded as at 15 to receive the threaded end of a nut 16 through which the shank A coiled ticularly to Figs. 2 to 5, the headais .provided substantially centrally thereof with a transverse bore 2O providing a chamber. for receiving a cylindrical valve member .21 which constitutes the main valve ofl the tool. Said valve member has a shank -22- extending through an opening 23 in t-he head, at one end of the bore 20, andV the 'shank 4has ref movably secured thereto a handle 24. A coiled compression spring 25, bearing -between the head and a collar` 26 engaging with the pin 24, serves to maintain the valve member 21 in operative position in the head. At the rear end of the head there is provided a longitudinal bore for receiving a threaded nipple 27'to which may be'attached a suitable conductor 2S for pressure fluid. Leading from the passage through the 'nipple 27, substantially centrally of the headV and across the valve chamber 2O therein, is apassage 29 opening into the rearward end of the cylinder 10. In the valve member 21 a port 30 is provided which is adapte-d to register with the interrupted'ends of the Ipassageway 29. It will be seen that when the valve member 21 is properly positioned by the handle 24, pressure fluid willbe periiiittedl to pass into the rear end of the cylinder to drive the piston forwardly therein.

To permit ofthe free and substantially7 unrestricted exhaust of air or pi'essiue-luid from the forward end of the cylinder, and thus enable'the piston'to strike 'an entirely uncushioned blow uponl the shank of 'the tool 1T, I providean exhaust port 31 (Figs. 7 and 8) at the `forward end of the' tool, said port 'being formed by suitablev registering apertures in the cylinder 10 fandthe sleeve 14. A if'alvelmembei" 32 is operable Vin a bore 33 which extends longitudinallyT through the sleeve 14 and through the lport 31,'the sleevebeing enlarged as at-14n for this purpose. This valve member is adapted to control the port 31 and is operatively associated with the valve operating mechaiiism in the head 13 so that when the valve 21 is movedinto a position to permit "ofl the [low of pressure-fluid to the rearend offthe cylinder, the valve member 32 is. 'simultaneously operated into position to open the exhaust port 3]. vandE permit of the free passage of air to the atmosphere from the forward end of the cylinder. lHerein the means for thus coordinating the movements of the' valve member' 32 withthat of the valve member 21 may comprise a mechanical connection consisting of a rod- 34 rigid with the valvemember 32 and having at its rear end a head1 (Fig 2) provided-with rack teeth 36. A pinion 3T rigid withfthe valve member 21Hmeshes with Ithe-.rack t-eetlii36. lPreferably a socket--38is provided in the lower Vface of the -head 13 -to-receive the pinion 37 which is made ofshghtly greater diameter than the valve member proper.

Extending longitudinally lof the head,4v to one side-thereofand tangeiitially ofthe-socket 33, there is provided a bore 39 adapted to neatlyreceive. the. head and guide it in its longitudinal movements.

To return the piston 11 to the rear or head end of the cylinder for another stroke, pressure-fluid is conducted to the forward end of the cylinder under the control of the operating means in theheadlf For this pur-` pose I provide-'in the head 13 a passage 40 communicating at one end with the passage through the nipple. 27 and thus with the source of pressure-fluid supply, and extendshown in Figs. 3 and, tot-he bore39fin the head (Fig. 2), forwardly of the liead 35 on the valve-operating rod 34. Between lthe head 13 and the sleeve 14 extends atube .41 having its rear end enteredinto''the 'forward end of the bore 39 and its forward end entering the reartend of theV bore' 33 in the sleeve 14. The tube 41 is, oi course, made of substantially greater diameterthan the rod 34 and 'is also of greater diameterthan the valve member 32 (Figs. 'T and S).to provide a clearance therebetween. .The valve member 32 thus does lnot restrict the passage of pressure-Huid through the tube. 41 into the bore 33.

In forder to conduct pressure-fluid from the tube 41l tothe forward end ofthe cylinder, and at the-same time-close communication between' the rport 31 andtheiiatmosphere,the valve member32 is cut away to lprovidel a cavity 42 upon its inner-iside. vSaidca'vity .42 is of such lengt-h lthatthe valve member 32E while :closingrthe port 31 Ato the atmosphere, (Fig. 8) lpermits ofthe passage 'of pressure-fluid by way of 'said cavity-:fl-'om the tube 41 into the'forward end of the cylinder.

` Forthe purpose of controlling the Lilow.

`of pressure-iuid throughithe passage= to -the'tube 41, .the main valve member 21 is provided with a port 43 arranged substantially atk right angles to=the port'30 inthe valve `member and adapted to-establish communication between the interruptedend portions of the passageway 40. Itk will'lbe apparent thatwhen the port 43 ofthe valve member is moved into position to connect the opposite portions of the .passageway 40, that the port 30 in the valvef memberwill vbe moved into position to cutuoif-thei'low of pressure-fluid tothe passageway 29.

f In order to-pei'mit of the exhaust of pressure-Huid from the-rear endV of the cylinder when the piston .11 isbeing returned thereto, the valve member 21 is constructed to Aprovide' an exhaust passagewayzcommu- .nicating with Jthe rear end ofthecylinder.

Thus the head 13 is provided witha,p`assageway 44 leading from the rear end of the cylinder to the bore 20 and adapted to-rcgingwithv an interruption bythe bore 20, as

liii'i ister with a port 45 (Figs. 4 and 5) opening into a chamber 46 provided in one end of the valve member 21 and opening to the atmosphere.

For the purpose of facilitating in the voperation of the tool, the positioning of the valve member 21 and hence of the valve member 32 at the forward end of the cylinder, the head 13 is provided upon its upper tace with a pair ot' lugs 47 and 48 oppositely disposed and adapted to be engaged by the handle 24 in its movements. the handle engages with one of the lugs as, tor example, the lug 47 (Fig. 5), the valve mechanism is in position to permit of the passage of pressure-fluid through the passage 29 and port 30 into the rear end of the cylinder to drive the piston forwardly therein, and to permit of the exhaust of pressure-fluid through the port 31 from the forward end of the cylinder, the valve member 32 being in the position shown in Fig. 7. On the other hand, when the handle 24 is moved into engagement with the lug 48, as shown in Fig. 1, pressure-fluid is per mitted to flow through the passage 40 and port 39 in the valve member into the passageway provided by the tube 41, and thence by way of the cavity 42 and the port 31 into the forward end of the cylinder. In this latter position of the parts also, the passage 44 leading from the rear end of the cylin-` der is connected with the port 45 and chamber 46 in the valve member, and thus the pressure-liuid in the rear end of the cylinder escapes to the atmosphere.

It will be seen that I have provided a tool of the type indicated which is of a very practical character. A strokeV of any desired length may be obtained for the piston; and'by reason of the provision of the eX- haust port at the forward end of the cylinder the necessity 4of the air traveling to the rear end of the cylinder for escape to the atmosphere, as is the case in tools of prior Then n construction, is avoided. Thus theefliciency of the tool in operation is materially inment of the parts is exceedingly simple.

The absence of bolts and screws for connecting the parts of the tool together is particu larly noteworthy, and because of the peculiar arrangement ot' the parts, a. single port at the forward end of the cylinder provides lfor the exhaust of pressure-fluid from the cylinder as the piston is driven tor-v wardly, as well as for the introduction of pressure-fluid into the cylinder to return the piston.

I claim as my invention:

A {luid-pressureactuated tool comprising, in combination, aftubular piston chamber, a piston therein, a valved head at one end of said chamber having therein admission and exhaust ports, a rotary valve member therein to control said ports, a tubular conduit connected at one end to the pressure Huid supply, the piston chamberl having a port Vin the yother end passing through said conduit transversely thereof to the atmosphere, a plunger valve in the conduit at its other end movable away from the port to close the conduit and to open the port to the atmosphere and movable toward the port to close the port to the atmosphere simultaneously admitting pressure fluid from the conduit to the piston chamber, a plunger head in the` conduit at thevfirst end thereof, a rod en-y closed by the conduit connecting the plunger valve and the plunger head, rack teeth on the plunger head, and a gear segment on the rotary valve member engaging the rack teeth, Vwhereby the radmission and exhaust of pressure fluid to yboth ends of the piston chamber are simultaneously controlled.

y In testimony whereof, I have hereunto set my hand.

f LOGEE n. Davis. 

